Windows环境下Flask+Apache部署出现'module' object is not callable错误求助

问题背景 #

近期在Windows系统中搭建Apache服务器部署Flask应用，部署步骤如下：

• 通过Apache Lounge下载Apache并解压至C:\Apache24；
• 在Python 3.7.7虚拟环境中安装mod_wsgi；
• 将mod_wsgi配置添加至httpd.conf文件；
• 在Apache的conf目录中创建应用配置文件。

Apache的error.log中出现如下错误：

[Fri Nov 11 18:44:00.985814 2022] [wsgi:error] [pid 9456:tid 1396] [client 127.0.0.1:58152] mod_wsgi (pid=9456): Exception occurred processing WSGI script 'J:/tools/pipecrew/ashish/workspace/tools/wsgi_scripts/shotgrid_ami_handler.wsgi'.
[Fri Nov 11 18:44:00.985814 2022] [wsgi:error] [pid 9456:tid 1396] [client 127.0.0.1:58152] TypeError: 'module' object is not callable
[Fri Nov 11 18:44:01.020776 2022] [wsgi:error] [pid 9456:tid 1392] [client 127.0.0.1:58153] mod_wsgi (pid=9456): Exception occurred processing WSGI script 'J:/tools/pipecrew/ashish/workspace/tools/wsgi_scripts/shotgrid_ami_handler.wsgi'., referer: http://fpservices.in/boom
[Fri Nov 11 18:44:01.020776 2022] [wsgi:error] [pid 9456:tid 1392] [client 127.0.0.1:58153] TypeError: 'module' object is not callable, referer: http://fpservices.in/boom

相关配置片段 #

1. Apache httpd.conf配置

LoadFile "J:/tools/rez_packages/python/3.7.7/platform-windows/python37.dll"
LoadModule wsgi_module "D:/virtual_python/python-3/mod_wsgi/lib/site-packages/mod_wsgi/server/mod_wsgi.cp37-win_amd64.pyd"
WSGIPythonHome "D:/virtual_python/python-3/mod_wsgi"

# Include Flask File
Include conf/shotgrid_ami_handler.conf

2. Flask应用配置文件（conf/shotgrid_ami_handler.conf）

<VirtualHost *:80>
    ServerName fpservices.in
    WSGIScriptAlias / J:/tools/pipecrew/ashish/workspace/tools/wsgi_scripts/shotgrid_ami_handler.wsgi
    <Directory J:/tools/pipecrew/ashish/workspace/tools/shotgrid_ami_handler>
        WSGIScriptReloading On
        Require all granted
    </Directory>
</VirtualHost>

3. WSGI文件（shotgrid_ami_handler.wsgi）

import sys

sys.path.insert(0, 'J:\\tools\\pipecrew\\ashish\\workspace\\tools')

from shotgrid_ami_handler import app as application

4. Flask应用代码（shotgrid_ami_handler.py）

from flask import Flask, request, Response

app = Flask(__name__)

@app.route('/boom', methods=['GET', 'POST'])
def boom():
    return 'boom!'

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=4576, debug=True)

错误原因与解决方法 #

核心问题 #

TypeError: 'module' object is not callable的本质是：mod_wsgi期望application是可调用的WSGI应用对象（即Flask的app实例），但当前导入的app实际是一个模块而非Flask实例。

触发原因 #

WSGI文件中sys.path添加的路径是J:\\tools\\pipecrew\\ashish\\workspace\\tools，而Flask应用代码所在目录是J:\\tools\\pipecrew\\ashish\\workspace\\tools\\shotgrid_ami_handler。执行from shotgrid_ami_handler import app时，Python将shotgrid_ami_handler识别为tools目录下的模块（可能存在同名文件夹或文件导入优先级问题），而非实际的Flask应用模块。

修复步骤 #

1. 调整WSGI文件的路径导入
   修改WSGI文件，将sys.path指向Flask应用所在的父目录，确保正确导入Flask实例：

   import sys
   
   # 指向包含Flask应用文件/目录的路径
   sys.path.insert(0, 'J:\\tools\\pipecrew\\ashish\\workspace\\tools\\shotgrid_ami_handler')
   
   from shotgrid_ami_handler import app as application
   

   若Flask应用代码直接在tools目录下的shotgrid_ami_handler.py文件中，需检查tools目录下是否有同名的shotgrid_ami_handler文件夹，避免Python优先导入文件夹作为模块。

2. 验证导入有效性
   可在WSGI文件中添加调试代码，确认导入内容：

   import sys
   sys.path.insert(0, 'J:\\tools\\pipecrew\\ashish\\workspace\\tools')
   
   import shotgrid_ami_handler
   print(type(shotgrid_ami_handler))  # 若输出<class 'module'>，说明导入的是模块而非实例
   print(dir(shotgrid_ami_handler))  # 查看模块成员，确认是否存在app属性
   

   执行后查看Apache的error.log，确认导入内容是否符合预期。

3. 规范目录结构
   确保文件目录结构清晰，避免同名冲突：

   J:\tools\pipecrew\ashish\workspace\tools\
   ├── wsgi_scripts\
   │   └── shotgrid_ami_handler.wsgi
   └── shotgrid_ami_handler\
       └── shotgrid_ami_handler.py  # 包含Flask app实例的文件
   

   或单文件结构：

   J:\tools\pipecrew\ashish\workspace\tools\
   ├── wsgi_scripts\
   │   └── shotgrid_ami_handler.wsgi
   └── shotgrid_ami_handler.py  # 包含Flask app实例的文件
   

内容的提问来源于stack exchange，提问作者Vicspidy